Regional flow in the Dakota aquifer: a study of the role of confining layers
J.D. Bredehoeft, C.E. Neuzil, P.C. Milly 1983 U.S. Geological Survey Water Supply Paper 2237 2237

This is a great paper describing the role of confining layers in regional flow systems using the historic work of N.H Darton in the Dakota Aquifer as a background to modern concepts and interpretations. This article would be useful for initiating a student project or class project on regional flow concepts.